1. Field of the Invention
The present invention relates to an apparatus for and a method of preventing a car from coming into collision with an object car running ahead or behind by measuring a car-to-object distance utilizing a pulse laser, comparing data indicative of the measured car-to-object distance with reference data, and controlling a speed of the car and giving an alarm to a driver.
2. Description of the Prior Art
Generally, most existing car collision prevention systems are adapted to recognize a distance between a car and an object car running ahead or behind in a non-contact manner utilizing a light beam. When the car-to-object distance is not more than a predetermined safety distance, such a car collision prevention system performs an automatic braking of the car or gives an alarm to the driver to prevent a car accident.
In such a car collision prevention system, the safety distance is predetermined, taking into consideration various conditions such as the speed of the car, the speed of the object car, the car-to-object distance, the braking distance of the car, the response time of the driver, etc. The car collision prevention system analyses the above-mentioned conditions to recognize a point of time when the car-to-object distance is not more than the predetermined safety distance. Upon recognizing the car-to-object distance being not more than the predetermined safety distance, the car collision prevention system gives an alarm to the driver or brakes the car automatically.
In the case of such a conventional car collision prevention system, however, the safety distance predetermined as a reference value is based on data associated with a normal road condition. For this reason, an insufficient safety distance may be established when the car runs on a curved road or on a sloped road. In such a situation, the light beam reflected by the object may be irregular. In these cases, the car collision prevention system has difficulty in appropriately coping with the road condition. As a result, there is a problem that the accident prevention function of the conventional car collision prevention system is degraded.